Explanation:
Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. Once a rock has been broken down, a process called erosion transports the bits of rock and mineral away. No rock on Earth is hard enough to resist the forces of weathering and erosion.
I believe the answer is C. Composition of earths core
Nitrogen fixing bacteria called rhizobia
- enzyme pepsin: chemically digests the proteins in the food, breaking down into amino acids
- hydrochloric acid (strong acid): provides an acid environment for pepsin and kills bacteria (food); without this acid, the stomach could not function properly.
♥ They make use of a control group because its something that they can look into, something to compare to. <span />
